Celebrating 70 Years of the KC-135: Enduring Lessons in Acquisition

Published Aug. 20, 2026
By Robert Marcell, Air Force Life Cycle Management Center History Office

Last month at AFLCMC’s tenth annual Life Cycle Industry Days gathering, Air Force Under Secretary Matt Lohmeier indicated that an “85 percent solution in the hands of our armed forces today is infinitely better than an unachievable 100 percent solution endlessly undergoing testing.”

But what can 85 percent actually give the warfighter?

In some cases, it gives them 70 years of legendary service… and counting.

LeMay’s Problem: The Call for a Jet-Powered Tanker
In late 1953, Air Force General Curtis LeMay, the hard-charging, cigar-chomping leader of Strategic Air Command (SAC), had a problem. It was SAC's job—it was his job—to ensure that the Air Force had the capability to strike back at the Soviet Union with waves of American bombers carrying nuclear weapons should the Soviets (who’d started making nukes of their own in 1949) ever attack the United States. Unfortunately, the new-fangled fleet of jet-engined bombers the Air Force was developing for SAC, consisting of B-52 Stratofortresses and B-58 Hustlers, would not be able reach all of their targets in the U.S.S.R.—an enormous country that spanned the gap between the Baltic Sea and the Black Sea in the west, and the Pacific Ocean in the east. The only way they could possibly do so was with the aid of en route aerial refueling.

The Air Force’s predecessor organizations in the Army had been experimenting with aerial refueling for decades by the start of the Second World War, but it was only after the war, and the establishment of an independent Air Force, that the Air Force acquired the Boeing KC-97 Stratofreighter. It was the first aircraft specifically procured as a tanker. By 1953, there were a couple hundred KC-97s in the Air Force, with hundreds more on the way, but there was an issue with this plane: Namely, the KC-97 was a piston-engined propeller-driven plane, while LeMay’s new bombers were all jets. The KC-97 was simply too slow to keep up with the planes it was supposed to be refueling.

In experimenting with refueling the jet-engined B-47 and F-84, KC-97 pilots discovered that they could get around the speed differences with a maneuver known as “tobogganing.” During this maneuver, the jets would come down from altitude to hook up to the KC-97 at its highest altitudes, and then both planes would enter a controlled dive (like sleds or toboggans going downhill) to increase the speed of the Stratofreighter. This was pretty inefficient though, with the jets wasting away a portion of the precious fuel they’d just taken on simply climbing back up to altitude after the process was done. Tobogganing also left the receiving jets vulnerable in potentially contested skies by forcing them low and slow.

To General LeMay, the “tobogganing” maneuver was a band-aid, not a solution. It wasn’t good enough. At SAC’s November 1953 annual requirements conference, LeMay called for 200 jet-powered tankers to be procured with fiscal year 1954 funds. If he wanted to refuel jet bombers, he’d do so with jet tankers: That’s all there was to it. Headquarters Air Force concurred and announced on May 5, 1954, that a turbo-jet tanker was required by the Air Force.

Selection of the KC-135: The 85 Percent Solution
After the decision was made to buy a jet tanker, the Air Force published its requirements for the plane and called for proposals from industry. The aviation giants of the day, including Lockheed, Boeing, Douglas, and others, drew up their designs and submitted their bids.

Two years earlier, however, in 1952, the Boeing Airplane Company had made a massive gamble. With $16 million of their own money (or approximately $200 million in today’s money), they had designed and built a prototype jet transport with no guarantee of ever actually selling it. This was the Boeing 367-80 (or “Dash 80”). From the start, the Dash 80 was intended for use as both a military tanker and a commercial airliner, so while the other companies were drafting their plans for a jet tanker in the summer of 1954, Boeing was already flying a real, physical demonstrator—with the Dash-80’s first flight occurring on July 15, 1954, right in the middle of the selection process.

Desperate for jet-engined tankers, the Air Force ordered 29 of Boeing’s airplane before the contest was even over, intending to use them as “interim” tankers to bridge the gap between present requirements and the eventual construction of whichever tanker won the bid.

That fall, in October and November of 1954, the Air Force determined in its evaluation of the submitted bids that Lockheed’s tanker best met its technical specifications. Lockheed’s proposal existed only on paper, however, which left the Air Force considering its options: Could the nation afford to wait years for Lockheed’s superior design to enter production while the Soviet Union seemed only to be growing in power? Or should the Air Force pick the “ready-to-go” 85 percent solution that was already roaring to life on Washington runways?

It is worth noting that this decision was being made years before the U.S. had its first operational Intercontinental Ballistic Missiles (ICBMs), and before the first nuclear missile-carrying submarines: The only way to deliver nukes to targets in the U.S.S.R. was bombers… and those bombers could only reach their targets with aerial refueling.

Given all of the above, the Air Research and Development Command (or ARDC, which, alongside the more logistics-minded Air Materiel Command, was a historical predecessor to today’s AFMC) recommended that the Air Force not buy Lockheed’s tanker. Yes, it was the best design, but the Air Force needed the best design that was ready right now. For that reason, ARDC argued that the Air Force should instead go with the more production-ready Boeing tanker, converting the 29 planes already ordered from Boeing to the final design configuration of the KC-135, and producing all future planes in that configuration from plane #30 on up. SAC was on board with this recommendation, too. In fact, SAC argued for it: In LeMay’s view, having two tanker fleets would unnecessarily complicate things. It would make the logistics of supporting both fleets much more complex, and it would be more expensive. Moreover, crew interchangeability requirements meant that all of SAC’s tanker pilots would have to train on both aircraft if the Air Force fielded two tanker fleets. In the end, the Air Force went with ARDC’s recommendation: Boeing’s gamble had paid off, and the KC-135 was selected for production. Boeing’s Dash-80 prototype would go on to enable Boeing’s 707 commercial airliner, as well.

First Flight: August 31, 1956
After the tanker contest was over and the decision was made, Boeing went to work on the world’s first jet-powered tanker, the KC-135 Stratotanker. On August 31, 1956, seventy years ago this year, the KC-135 made its maiden flight out of Boeing’s plant in Renton, Washington (near Seattle). It was early on a Friday afternoon, temps were in the 70s, and it was mostly sunny and dry. The aircraft, which was named the City of Renton, was flown by Richards L. “Dix” Loesch, Boeing’s senior experimental test pilot, and Alvin M. “Tex” Johnston, Boeing’s chief of flight test. Johnston and Loesch also flew Boeing’s original “Dash 80” prototype in 1954, and Johnston flew the 707 airliner’s maiden flight in 1957. An hour and 19 minutes after takeoff, the City of Renton landed at Seattle’s Boeing Field.

Conclusions
In the decades since this first flight, the KC-135, and the rest of the versatile C-135 family (which originally consisted of 820 aircraft, with 732 of them being KC-135s), has proven highly adaptable to the needs of the nation. After numerous larger- and smaller-scale modification and modernization efforts, today’s KC-135Rs and KC-135Ts are highly capable and sophisticated weapon systems. Other C-135 systems have had jobs ranging from command and control (the EC-135) to reconnaissance (the RC-135) to atmospheric testing (the “nuke sniffing” WC-135). NASA even used a KC-135 as a “Vomit Comet” for simulating weightlessness with parabolic flights until it was replaced by a 737.

And while the KC-135, fortunately, never had to enable a doomsday scenario like the one LeMay was preparing for, the platform remains a critical enabler of the U.S. Air Force’s ability to be anywhere in the world on short notice today. When the last KC-135 was delivered to the Air Force in 1965, the KC-135 fleet was the largest tanker fleet in the world. Decades later the Air Force’s KC-135 fleet is still the world’s largest tanker fleet. The KC-135 is not expected to fully retire until at least the 2040s, which means that it will continue to enable the global reach of American Airpower for many years yet to come.

Not bad for an “85 percent solution.”

55-3118: The birth of a 60-year legacy

Aircraft 55-3118 sits on display, Aug. 13, 2015, near the east gate of McConnell Air Force Base, Kan. The aircraft completed its first flight on Aug. 31, 1956 and was the first of 732 KC-135 Stratotankers delivered to the Air Force. Nicknamed “City of Renton” after the Washington city where it was manufactured, the Stratotanker was retired after decades of service in the Air Force and more than 40 years after its first flight. (U.S. Air Force photo by Airman 1st Class Jenna Caldwell)

An airman wearing a headset sits in a dim cockpit while working on a control panel illuminated by white, green and orange lights. — Cockpit View

An Air Force pilot conducts preflight checks aboard a KC-135 Stratotanker during Beverly Beach at Kadena Air Base, Japan, Aug. 4, 2026. The exercise ensures forward-deployed forces in the Pacific are ready to protect and defend the U.S., allied and partner interests at a moment's notice.

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A KC-135 Stratotanker assigned to the 6th Air Refueling Wing, taxis the flightline at MacDill Air Force Base Florida, July 3, 2026. The aircraft carried Airmen assigned to the 50th and 91st Air Refueling Squadrons, returning from a scheduled deployment providing critical aerial refueling capabilities to joint and coalition forces. (U.S. Air Force photo by Senior Airman Monique Stober)

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U.S. Air Force F-35A Lightning IIs, F-16 Fighting Falcons, F-22A Raptors and a KC-135 Stratotanker conduct sorties over the Joint Pacific Alaska Range Complex near Eielson Air Force Base, Alaska, Aug. 13, 2026. This flight gave Gen. Gregory Guillot, , commander of the North American Aerospace Defense Command (NORAD) and U.S. Northern Command (USNORTHCOM), and Danish Gen. Michael Hylegaard, Chief of Defense, a firsthand look at Alaska's unique training environment, preparing U.S. and allied forces to operate in extreme cold-weather conditions while advancing security and cooperation in the Arctic. (Courtesy Photo)

55-3118: The birth of a 60-year legacy

55-3118: The birth of a 60-year legacy

Cockpit View

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